High speed chronic total occlusion crossing devices

ABSTRACT

An occlusion crossing device includes an outer shaft, an inner shaft, an optical fiber, and a handle attached to the inner shaft and the outer shaft. The inner shaft extends within the outer shaft. The inner shaft includes a drill tip at a distal end thereof. The optical fiber extends within the inner shaft substantially along a central axis of the inner shaft. The distal tip of the optical fiber is attached to the drill tip. The handle is configured to rotate the inner shaft and drill tip at speeds of greater than 500 rpm.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/324,325, filed Jan. 6, 2017, titled “HIGH SPEED CHRONIC TOTALOCCLUSION CROSSING DEVICES,” now U.S. Pat. No. 10,357,277, which is anational phase application under 35 USC 371 of International PatentApplication No. PCT/US2015/039585, filed Jul. 8, 2015, titled “HIGHSPEED CHRONIC TOTAL OCCLUSION CROSSING DEVICES,” now InternationalPublication No. WO 2016/007652, which claims priority to U.S.Provisional Patent Application No. 62/022,101, titled “HIGH SPEEDCHRONIC TOTAL OCCLUSION CROSSING DEVICES,” and filed Jul. 8, 2014 andU.S. Provisional Patent Application No. 62/073,850, titled “HIGH SPEEDCHRONIC TOTAL OCCLUSION CROSSING DEVICES,” and filed Oct. 31, 2014, theentire contents of each are incorporated by reference herein.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

BACKGROUND

Peripheral artery disease (PAD) and coronary artery disease (CAD) affectmillions of people in the United States alone. PAD and CAD are silent,dangerous diseases that can have catastrophic consequences when leftuntreated. CAD is the leading cause of death for in the United Stateswhile PAD is the leading cause of amputation in patients over 50 and isresponsible for approximately 160,000 amputations in the United Stateseach year.

Coronary artery disease (CAD) and Peripheral artery disease (PAD) areboth caused by the progressive narrowing of the blood vessels most oftencaused by atherosclerosis, the collection of plaque or a fatty substancealong the inner lining of the artery wall. Over time, this substancehardens and thickens, which may interfere with blood circulation to thearms, legs, stomach and kidneys. This narrowing forms an occlusion,completely or partially restricting flow through the artery. Bloodcirculation to the brain and heart may be reduced, increasing the riskfor stroke and heart disease.

Interventional treatments for CAD and PAD may include endarterectomyand/or atherectomy. Endarterectomy is surgical removal of plaque fromthe blocked artery to restore or improve blood flow. Endovasculartherapies such as atherectomy are typically minimally invasivetechniques that open or widen arteries that have become narrowed orblocked. Other treatments may include angioplasty to open the artery.For example, a balloon angioplasty typically involves insertion of acatheter into a leg or arm artery and positioning the catheter such thatthe balloon resides within the blockage. The balloon, connected to thecatheter, is expanded to open the artery. Surgeons may then place a wiremesh tube, called a stent, at the area of blockage to keep the arteryopen.

Such minimally invasive techniques (e.g., atherectomy, angioplasty,etc.) typically involve the placement of a guidewire through theocclusion. Using the guidewire, one or more interventional devices maybe positioned to remove or displace the occlusion. Unfortunately,placement of the guidewire, while critical for effective treatment, maybe difficult. In particular, when placing a guidewire across anocclusion, it may be difficult to pass the guidewire through theocclusion while avoiding damage to the artery. For example, it is oftendifficult to prevent the guidewire from directing out of the lumen intothe adventitia and surrounding tissues, potentially damaging the vesseland preventing effective treatment of the occlusion.

As a result, occlusion-crossing devices, intended to assist in thepassing of the guidewire through the occlusion, have been developed.Many of the devices, however, are ill equipped to be used with imaging,thereby making placement of the guidewire cumbersome and difficult.Moreover, many of the occlusion-crossing devices are too large to beused in small-diameter peripheral arteries or in coronary arteries.

Accordingly, occlusion crossing catheter devices designed to addresssome of these concerns are described herein.

SUMMARY OF THE DISCLOSURE

Described herein are occlusion-crossing devices having a low profile anda distal drill tip. In some embodiments, an articulating feature canprovide for steering or directionality of the device. In someembodiments, an inner shaft can be removable from an outer shaft.

In general, in one embodiment, an occlusion crossing device includes anouter shaft, an inner shaft, an optical fiber, and a handle attached tothe inner shaft and the outer shaft. The inner shaft extends within theouter shaft. The inner shaft includes a drill tip at a distal endthereof. The optical fiber extends within the inner shaft substantiallyalong a central axis of the inner shaft. The distal tip of the opticalfiber is attached to the drill tip. The handle is configured to rotatethe inner shaft and drill tip at speeds of greater than 500 rpm.

This and other embodiments can include one or more of the followingfeatures. The inner shaft and optical fiber can be removable from theouter shaft. The handle can include a luer lock configured to lock andunlock the inner shaft relative to the outer shaft. The outer shaft caninclude an articulating feature configured to allow the outer shaft tobend. The articulating feature can be activated by moving the innershaft along the central axis relative to the outer shaft. Thearticulating feature can include a backbone and a plurality ofcircumferential cuts. The inner shaft can include an annular memberconfigured to engage with an inner lip of the outer shaft to bend theouter shaft when the inner shaft is pushed distally. The inner shaft caninclude an annular member configured to engage with an inner lip of theouter shaft to bend the outer shaft when the inner shaft is pulledproximally. The outer shaft can include a preformed bend therein. Theouter shaft can further include a marker positioned with respect to thepreformed bend such that an orientation of the outer shaft can bedetermined during imaging. The outer shaft can include a transparentdistal portion configured to allow imaging with the optical fibertherethrough. The handle can be configured to rotate the inner shaft anddrill tip at speeds of greater than 1,000 rpm. The handle can beconfigured to rate the inner shaft and drill tip at speeds of greaterthan 500 rpm such that images can be generated from the optical fiber ata rate of greater than or equal to 8 frames per second. The opticalfiber can be a common path optical coherence tomography fiber. The drilltip can include a plurality of spiral cutting edges. The drill tip canbe a substantially smooth frusto-conical tip. The imaging device canfurther include a monorail guidewire lumen extending along the outershaft. An outer diameter of the outer shaft can be less than 0.08inches.

In general, in one embodiment, a method of crossing an occlusionincludes: (1) inserting a device into a vessel having an occlusiontherein; (2) rotating an inner shaft of the device relative to an outershaft of the device such that a drill tip on the inner shaft drillsthrough the occlusion; and (3) generating images with an optical fiberextending through the inner shaft at a rate of greater than or equal to8 frames per second while rotating the inner shaft.

This and other embodiments can include one or more of the followingfeatures. The method can further include removing the inner shaft fromthe outer shaft, and inserting a guidewire through the outer shaft. Themethod can further include bending a distal end of the device in orderto steer the device through the vessel. Bending the distal end cancomprise pushing or pulling on the inner shaft. The method can furtherinclude orienting a bend in the outer shaft in a desired direction. Themethod can further include using a marker on the device to orient thebend. Rotating the inner shaft can comprise rotating at more than 500rpm.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe claims that follow. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings of which:

FIGS. 1A-3B show an occlusion crossing device having an articulatingfeature.

FIGS. 4A-5C show an occlusion crossing device having separable inner andouter shafts.

FIGS. 6A and 6B are exemplary block diagrams of drive systems for thecatheters described herein.

FIGS. 7A-7B show an exemplary method for detecting the position of thedriveshaft of a catheter.

FIGS. 8A-8B show articulation of an occlusion crossing device having anarticulating feature and separable inner and outer shafts.

FIGS. 9A and 9B show the inner shaft of the occlusion crossing device ofFIGS. 8A-8B positioned inside of the outer shaft for cutting andimaging.

FIG. 10 shows the outer shaft of the occlusion crossing device of FIGS.8A-8B with the inner shaft removed.

FIGS. 11A and 11B show an exemplary handle for use with the occlusioncrossing device of FIGS. 8A-8B.

FIGS. 12 and 13 show another exemplary handle for use with the occlusioncrossing device of FIGS. 8A-8B.

FIGS. 14A-14C show the distal portion of another embodiment of anocclusion crossing device.

FIG. 15 shows the occlusion crossing device FIGS. 1A-3B with a monorailguidewire lumen.

DETAILED DESCRIPTION

Described herein are occlusion-crossing devices having a low profile soas to be usable in small-diameter arteries and coronary arteries, e.g.,through a 5 French catheter or smaller. In general, the devicesdescribed herein can have on-board imaging, such as optical coherencetomography (OCT) imaging. The optical fiber for OCT imaging can extendsubstantially along the central axis of the device, thereby decreasingthe profile of the device and allowing for rotation at high speeds. Thedevices can also include a rotatable pointed tip, allowing for forwarddrilling. In some embodiments, the device can include an articulatingdistal end to enable steering of the device.

Referring to FIGS. 1A-3B, in one embodiment, an exemplary catheter 100includes an outer shaft 122 and an inner driveshaft 131 connected to adistal tip 103. The elongate outer shaft 122 can be hollow and can havean inner diameter of approximately 1 mm and an outer diameter ofapproximately 1.5 mm. In some embodiments, the outer shaft 122 can havea coiled construction, whereby the coils are wound by laying one coilover another. For example, the shaft 122 can include at least two coillayers. Further, the coil layers can be counter-wound, such that onecoil layer, such as the inner coil layer, has a left hand lay andanother layer, such as the outer coil layer, has a right hand lay. Thecoil can provide torque in the direction that tightens the outer layer,cinching down on the inner layer. A third counter wound coil can beadded to generate torque in both directions. In another embodiment, theshaft 122 is made of a braided wire reinforced polymeric shaft. In yetanother embodiment, the shaft 122 can be a laser-cut tube. The outershaft 122 can further include one or more imaging windows 144 at adistal end thereof.

A bushing 124 (see FIG. 1D) can be attached to the shaft 122, such asthrough a tab and slot mechanism 148. The bushing 124 can act as abearing surface relative to the inner shaft or tip 103. Further, thebushing 124 can include edges or lips 151, 152 on either side configuredto interact with the inner driveshaft 131 or the tip 103, as discussedfurther below.

The tip 103 can be configured, for example, to separate, dissect, orshred tissue. In some embodiments, the tip 103 can include sharpspiraling flutes 113 that come to a point in the center of the device.Further, the flutes 113 can be angled such that they have sharper edgeswhen rotated in one direction than in another direction. As a result,the tip 103 with flutes 113 can have an active and passive modesdepending upon the direction of rotation of the tip 103. In passivemode, the tip 103 with flutes 113 can be less aggressive, providingblunt dissection of tissue. In active mode, the tip 103 with flutes 113can be more aggressive, providing cutting and auguring to make its waythrough harder material. In some embodiments, as described further belowwith respect to FIGS. 14A and 14B, the distal tip 103 can have a smoothangled surface that is non-fluted.

The inner driveshaft 131 (see FIG. 1D) can be connected to the distaltip 103 and can extend down the center of the outer shaft 122. The innerdriveshaft 131 can be configured to rotate in either a single directionor in both the clockwise and counterclockwise directions so as to rotatethe tip 103 relative to the shaft 122 (about the bushing 124) in eithera single direction or in the clockwise or counterclockwise direction.Annular rings 174, 172 can be positioned around a distal portion of theinner driveshaft 131 and/or the tip 103. The rings 174, 172 can bepositioned against the edges 151, 152 of the bushing 124. The annularbushing 124 can allow relative rotation of the inner driveshaft 131relative to the bushing 124 while preventing axial movement (andallowing for articulation in some embodiments, as described furtherbelow).

In some embodiments, a distal portion of the outer shaft 122 can includean articulating feature 145. As shown in FIGS. 1A and 1B, thearticulating feature 145 can include one or more backbones 245 a, b anda series of circumferential cuts 247 and 295. The one or more backbonescan be positioned on only one side of the catheter (e.g., span less than180 degrees, less than 150 degrees, or less than 90 degrees). In someembodiments, and as shown in FIG. 1A, a series of small circumferentialcuts 295 can extend between the two backbones 245 a, b in order toprovide added flexibility during bending. The circumferential cuts 247,295 can be configured as incomplete rings or spirals about the outershaft 122. Referring to FIG. 1B, in some embodiments, thecircumferential cuts 247 can include one or more breaks 297 a,b thereindesigned to provide additional tensile strength and compressionresistance for the articulating feature 145.

The articulating feature 145 can be attached to the inner driveshaft 131such that movement of the driveshaft 131 can activate the articulatingfeature. Further, in some embodiments, a handle 200 (see FIGS. 2B and3B) can be used to activate movement of the driveshaft 131.

Referring to FIGS. 2A-2B, as the driveshaft 131 is pushed distally, theannular ring 172 can push distally on the proximal lip 152 of thebushing 124 (see FIG. 1D), causing the circumferential cuts 247 tospread apart or open while the backbones 245 a,b maintain their length(and the circumferential cuts 295 move closer together). As a result,the articulating feature 145 can bend towards the backbones 245 a,b. Asshown in FIG. 2B, this bending mechanism can be activated on the handle200, such as by moving a ring 303 distally and/or pushing or moving abutton or lever.

Likewise, referring to FIGS. 3A-3B, as the driveshaft 131 is pulledproximally, the annular ring 174 can hit the distal lip 151 of thebushing 124. As further distal force is applied by the driveshaft 131,the circumferential cuts 247 can begin to move closer together and/orthe material between the cuts 247 can overlap while the backbones 245a,b maintain their length (and the cuts 295 move further apart). As aresult, the articulating feature 145 can bend towards thecircumferential cuts 247 and away from the backbones 245 a,b. As shownin FIG. 3B, this bending mechanism can be activated on the handle 200,such as by moving the ring 303 proximally and/or pushing or moving abutton or lever.

The bending movement of the articulating feature 145 can advantageouslyallow the device 100 to be steered when used in the vessel, such as forre-entry if the tip extends out of the occlusion or lumen. In someembodiments, the catheter 100 can be configured to bend in only onedirection by either pushing or pulling on the driveshaft 131 and returnto the straight configuration shown in FIG. 1A by movement of thedriveshaft 131 in the opposite direction.

The catheter 100 can further include an imaging element 199 attached tothe driveshaft 131 and configured to rotate therewith. The imagingelement 199 can be the distal end of an OCT fiber 119 extending down thecenter of the driveshaft 131. The imaging element 199 can provideimaging (through windows 144) as the catheter 100 is used in the vessel,thereby assisting in occlusion crossing.

Referring to FIG. 15, in some embodiments, a monorail guidewire lumen1505 can extend along the outer shaft 122. The guidewire lumen 1505 canrun, for example, between the two backbones 245 a,b so as to not addadditional stiffness to the flexible area with the circumferential cuts247.

In some embodiments, the catheter 100 can be used with a sheath. Thesheath can be hollow and include a hemostasis valve attached at theproximal end with a flush port on the side to facilitate flushingthrough the sheath. The sheath can also facilitate guidewire placementto the target site, particularly for embodiments of the catheter 100that do not include a monorail guidewire lumen. That is, the catheter100 can be used to cross the occlusion, the sheath can be placedthereover, the device removed, and then the guidewire can be introduced.

Referring to FIGS. 4A-5C, in another embodiment, an exemplary catheter300 includes an inner shaft 311, an outer shaft 322, and a distal tip303 connected to the inner shaft 311. Further, the outer shaft 322 canbe separable from the inner shaft 311. For example, the inner shaft 311can include a luer connector near the proximal end that is attachableand detachable from a luer connector on a proximal end of the outershaft 322, as described below with respect to handle 900.

In some embodiments, a distal portion 313 of the outer shaft 322 can beclear or transparent, such as made of a clear or transparent plastic, inorder to allow imaging therethrough. In some embodiments, the outershaft 322 can further include a preformed bend 329 therein to helporient or steer the device. A marker 315, such as a metal marker, canextend within the distal portion 313 to indicate the relativeorientation of the catheter 300 when in use. For example, as shown inFIG. 4B, the innermost portion of the bend 329 can align with the marker315.

Further, in some embodiments, the inner shaft 311 can movelongitudinally within the hollow outer shaft 322 by sliding a ring on ahandle (such as handle 200) connected to the catheter 300 to allow theinner shaft 311 to be exposed (as shown in FIGS. 4A-4B) or fully covered(as shown in FIGS. 5A-5C). In use, the inner shaft 311 can thus beextended out of the outer shaft to help drill through the occlusion andpulled in when dissection is not required (or when only blunt dissectionis required). In some embodiments, the inner shaft 311 can be configuredto be fixed at various points relative to the outer shaft 322 so as tovary the amount of exposed tip 103. Further, the shaft 311 can be fullyremoved from the outer shaft 322 to allow for placement of a guidewiretherethrough.

Further, the device 300 can include an imaging element 399 similar to asdescribed above with respect to device 100. The catheter 300 can beconfigured to image with the imaging element 399 both when the innershaft 311 is extended distally out of the outer shaft 322 and when theinner shaft 311 is positioned within the outer shaft 322 (through thetransparent distal portion 313).

The device 300 can further or alternatively include any of the features,materials, and/or dimensions described above with respect to device 100.

Referring to FIGS. 8A-10, in another embodiment, an exemplary catheter800 can include both a separable inner shaft 811 and outer shaft 822 andan articulating feature 845 on the distal end of the outer shaft 822.

Referring to FIGS. 8A-8B, the articulating feature 845 can include abackbone 945 and a series of circumferential cuts 947. Further, as shownin FIG. 9A, a collar 860 attached to the outer shaft 822 can include aninner ledge 862 configured to extend radially inwards relative to theouter shaft 822. Likewise, the inner shaft 811 can include an annularmember 872, such as a plastic bearing, that has a greater diameter thanthe rest of the inner shaft 811. Thus, when the inner shaft 811 ispushed distally, the annular member 872 of the inner shaft 811 can pushagainst the inner ledge 862 of the collar 860. As a result, the outershaft 822 can bend at the cuts 947 towards the backbone 945 (as shown bythe arrows in FIG. 9A).

As shown in FIG. 10, the inner shaft 811 can be fully removable from theouter shaft 822 and collar 860 by pulling the inner shaft 811proximally. By doing so, the outer shaft 822 can be used as a sheath,e.g., for guidewire placement.

Further, the inner shaft 811 can include an imaging element 877 elementsimilar to as described above with respect to devices 100 and 300 thatis rotatable with the inner shaft 811. The imaging element 877 can imagethrough imaging windows 866 in the collar 860. Further, the inner ledge862 can also function to properly align the imaging element 877 with theimaging windows 866 when the inner shaft 811 is within the outer shaft822.

The inner shaft 811 can include a rotatable distal tip 803 similar to asdescribed above with respect to devices 100 and 300. Likewise, thedevice 800 can alternatively or additionally include any of thematerials and dimensions described above with respect to devices 100 and300.

Referring to FIGS. 11A-11B, a handle 900 can be used to operate thedevice 800. The handle 900 can include a luer lock 883 configured tolock the inner shaft 811 and outer shaft 822 together longitudinally.The luer lock 883 can be configured to provide some relativelongitudinal movement between the outer shaft 822 and the inner shaft811 such that the inner shaft 811 can still move a small distance, suchas between about 0.125 inches to 0.2 inches, to activate thearticulating feature 845. For example, the inner shaft 811 can includean accordion or elastomeric segment to provide the additional relativemovement. The actual displacement distance depends on the diameter ofthe outer shaft of the catheter, the degree of bending that is desiredand the elongation/compression of the outer and inner shaft,respectively. The larger the diameter of the outer shaft, the greaterthe desired degree of bending, and the more compression/elongation ofthe shafts, the greater the required amount of displacement. Further,the luer lock 883 can be configured to allow the inner shaft 811 torotate freely within the outer shaft so as to provide rotation of thesharp distal tip 803 connected to the inner shaft 811. The luer lock 883can be configured such that the outer shaft can be rotated relative tothe position of the handle. With the shaft in the articulated position,rotating the outer shaft will direct the catheter around or towardsobstacles during use. If the luer lock 883 is disconnected, as shown inFIG. 11B, the inner shaft 811 can be pulled out of the outer shaft 822by the handle, leaving the outer shaft 822 in place, such as forguidewire placement.

The handle 900 can further include a lever 885 or ring configured tocontrol the axial movement of the inner shaft 811 (and thus thearticulation of the device 800). In some embodiments, the lever 885 caninclude a locking mechanism that allows the device 800 to stay bent at aset angle. The handle 900 can also include a rotation element 893attached to the outer shaft 822 and configured to rotate the outer shaft822, such as 360 degrees, to position the bend of the device 800 in thedesired orientation.

Another exemplary handle 1000 is shown in FIGS. 12-13. The handle 1000can include many of the features of handle 900. A slide button 1085 canbe used to control the axial movement of the inner shaft. The rotationelement 1093 can be configured to rotate the outer shaft 822.

Furthermore, in some embodiments, the connection between the outer andinner shafts within the handle can be configured such that the two shaftsnap together, axially fixing the proximal ends together, but allowingthem to rotate independently. In other embodiments, a third elementcould be used to key, link, or peg the two shafts together.

Features of the handles 900, 1000, though described for use withcatheter 800, can likewise be used with catheters 100, 300.

The distal end of another embodiment of a catheter 1400 is shown inFIGS. 14A-14B. The catheter 1400 is similar to catheters 100, 300, 800except that it includes a smooth distal tip 103 and a molded distalportion 1410. Thus, the distal tip 103 can have a smooth angled surface1413 that is non-fluted and comes together in a slightly convex distalpoint 1415 (i.e., the tip can be frusto-conical). The distal tip 103 ofFIGS. 14A, 14B can advantageously provide less aggressive drillingthrough the occlusion. The distal tip 103 of FIGS. 14A and 14B can beused in place of any of the distal tips described with respect tocatheters 100, 300, 800. Likewise, the catheter 1400 can include amolded distal portion 1422. The molded distal portion 1422 can besimilar to the distal end of the catheter 300 and can include a bushing1424, a transparent section 1422, and the scaffolding 1452 of the outershaft. Further, an imaging fiber 1499 can run down the central axis ofthe device, as described above with respect to other embodiments. Any ofthe features of catheter 100, 300, 800 can be used in addition to, or asan alternative to, the features described with respect to catheter 1400.Likewise, the catheter 1400 can be used with a handle having some or allof the features of handles 200, 900, or 1000.

In some embodiments, all or a portion of the outer shaft of thecatheters described herein can be clear to allow imaging therethrough.Further, in some embodiments, the catheters described herein can includea balloon to occlude for better imaging. The balloon can be a clearballoon to allow imaging therethrough.

As described above, the catheters 100, 300, 800, 1400 can include animaging element. The imaging element can include an optical fiber, suchas an optical coherence tomography (OCT) imaging fiber. The opticalfiber can extend within the driveshaft or inner shaft so as to extendsubstantially along the central axis of the catheter for the entirelength of the fiber. The fiber can be attached at the distal end of thedriveshaft or inner shaft and/or the distal tip, but can be otherwisefree to float within the driveshaft. The imaging fiber can transfer anOCT signal for imaging of the vessel in which the device is placed. Insome embodiments, the imaging fiber can have a polyimide coatingtherearound within the length of the driveshaft to support and protectthe fiber as it spins within the driveshaft. Further, the handlesdescribed herein can be configured to accommodate a certain amount ofslack in the fiber to facilitate extension and retraction of drive shaftagainst hollow shaft.

The imaging element can further include a mirror oriented at an angle(such as a 30-60 degree angle, e.g., 45 degrees) with respect to thecentral axis of the fiber such that light coming out of the fiber willbounce off the mirror and into the adjacent tissue. Glue can be used tohold the distal end of the optical fiber in place. The glue can have arefractive index configured to be appropriately mismatched with therefractive index of the fiber, as described in U.S. patent applicationSer. No. 12/790,703, titled “OPTICAL COHERENCE TOMOGRAPHY FOR BIOLOGICALIMAGING,” filed May 28, 2010, Publication No. US-2010-0305452-A1; andInternational Patent Application No. PCT/US2013/031951, titled “OPTICALCOHERENCE TOMOGRAPHY WITH GRADED INDEX FIBER FOR BIOLOGICAL IMAGING,”filed Mar. 15, 2013, both of which are incorporated by reference intheir entireties. Further, the glue can have a meniscus shape along itsouter edge, as described in International Patent Application No.PCT/US2013/031951 titled “OPTICAL COHERENCE TOMOGRAPHY WITH GRADED INDEXFIBER FOR BIOLOGICAL IMAGING,” filed Mar. 15, 2013, incorporated byreference herein. The meniscus shape can advantageously ensure that thelight reflected back from the surface of the glue and back into thefiber is significantly less than the light referenced.

The driveshaft or inner shaft, and thus the imaging element or opticalfiber, can be configured to rotate continuously at high speeds, such asgreater than 500 rpm, greater than 600 rpm, greater than 700 rpm,greater than 800 rpm, greater than 900 rpm, or greater than 1,000 rpm,e.g., between 500-1,000 rpm, in one or both directions to provide OCTimaging around the inner circumference of the vessel. Such high speedrotation in a single direction or in different directions as chosen bythe user (as opposed to requiring rotation alternately in bothdirections to manage the optical fiber) allows for the gathering ofimage data more quickly, thereby providing more accurate and up-to-dateimages during use of the device 100. For example, images can begenerated at a rate of greater than 6 frames per section (fps), such asgreater than or equal to 8 fps or greater than or equal to 10 fps, suchas approximately 16.67 fps. In an exemplary embodiment, the rate ofLaser sweep, such as approximately 20 KHz, can be configured to keep upwith at 16.67 frames per second with about 1200 lines per frame.

Advantageously, because the optical fiber runs through the center of thecatheters described herein, the catheters can be small in diameter. Forexample, the outer diameter of the catheters described herein can beless than 0.10″, such as less than 0.08″, such as less than 0.07″, lessthan 0.06″, or less than 0.05″. Accordingly, the catheters describedherein can advantageously be used in small-diameter peripheral arteriesand coronary arteries.

In some embodiments, the catheters described herein can be configured tobe attached to a drive system. The drive system can include a rotaryoptical junction configured to rotate the fiber. Exemplary drive systemsthat could be used in conjunction with the devices herein are describedin U.S. patent application Ser. No. 13/654,357, titled “ATHERECTOMYCATHETERS AND NON-CONTACT ACTUATION MECHANISM FOR CATHETERS,” filed Oct.17, 2012 and International Patent Application No. PCT/US2013/032089,titled “ATHERECTOMY CATHETER DRIVE ASSEMBLIES,” filed Mar. 15, 2013,each incorporated herein by reference in its entirety.

In some embodiments, the drive system can communicate with the controlsystem via a communication bus, which in some embodiments can be a CANbus 2.0B. This communication can be employed to convey status to thecontrol system or console, such as direction, speed, run status, andother information. It can also be employed to send control informationto the drive system, such as run command, speed, direction, and settingof parameters for compensations of mechanical characteristics of thecatheters. Referring to FIG. 6A, in one embodiment, a drive processor1601 is used as the main controlling element for the drive system. Thedrive processor 1601 controls the motor 1603 through a motor controller1602, which receives commands and returns status from/to the driveprocessor 1601. The drive processor 1601 can, in addition to simplespeed and direction control, also implement algorithms to optimizecatheter performance. The drive processor 1601 communicates with thecontrol system (e.g., the console for the device) via the CAN controller1604 to send and receive commands and status. In addition, in thisembodiment a switch 1605 on the drive processor 1601 housing allowslocal control of the run state. The switch 1605 can be replaced withalternative hardware inputs, such as buttons, toggles, or knobs.

Further, in some embodiments the drive system can communicate with thecatheter via NFC or RFID to obtain information about the catheter. As anexample, this information can include catheter type, optimal rotationalspeed and direction, serial number, amongst many possible parameters.Referring to FIG. 6B, the drive system communicates with the cathetervia a NFC/RFID reader 1606 and a NFC/RFID tag 1607 in the catheter toobtain information stored in the tag.

The drive system can be configured to allow the driveshaft and cutter torotate continuously in the clockwise or the counterclockwise directiondepending upon user preference. Therefore, in some embodiments, thedrive system can include a user-addressable switch, such as a toggle, toset the desired direction.

Further, in some embodiments, the drive system can include a mechanismto determine the amount of rotation of the driveshaft in the clockwiseor counterclockwise directions. Referring to FIGS. 6A and 6B, in oneembodiment, for example, the drive system can provide informationrelated to the direction of the motor. Speed and direction can be sensedby the control system (or console) by a data line in the umbilical,which can be a dedicated line or a multiplexed signal. The dedicatedline can carry an analog or a digital signal. In one embodiment, adedicated voltage line carries six discrete velocities (vectorspeed+direction) that are interpreted by the control system or consolein order to infer speed and direction of the catheter.

Referring to FIGS. 7A-7B, in on embodiment, a flag in the drive systemcan include either an asymmetric design or an asymmetric positioning ofthe flags around the motor (see FIG. 7A). A controller can then sensemotor direction by detecting the distinct series of flag spacing and/orwidth, as shown in FIG. 7B.

Further, in some embodiments, the drive system can be configured torotate the driveshaft at several discrete rates and/or include a knob toallow for user-chosen continuously variable speeds.

Any of the catheters described herein can be shape-set or includeshape-set features to enhance trackability and navigability.

As used herein, an imaging element can include the OCT optical fiber,such as the distal end of the optical fiber, as well as the mirror andadhesive used to hold the mirror and optical fiber in place.

As described above, the catheters described herein can include opticalcoherence tomography imaging, such as common path OCT. Such OCT systemsare described in U.S. patent application Ser. No. 12/829,267, titled“CATHETER-BASED OFF-AXIS OPTICAL COHERENCE TOMOGRAPHY IMAGING SYSTEM,”filed Jul. 1, 2010, Publication No. US-2010-0021926-A1; U.S. patentapplication Ser. No. 12/790,703, titled “OPTICAL COHERENCE TOMOGRAPHYFOR BIOLOGICAL IMAGING,” filed May 28, 2010, Publication No.US-2010-0305452-A1; and International Patent ApplicationPCT/US2013/031951 titled “OPTICAL COHERENCE TOMOGRAPHY WITH GRADED INDEXFIBER FOR BIOLOGICAL IMAGING,” filed Mar. 15, 2013, all of which areincorporated by reference in their entireties. Alternatively, othertypes of imaging could be used with the catheters described herein. Forexample, the devices described herein could be configured to work withinfrared spectroscopy or ultrasound.

The catheters 100, 300, 800, 1400 described herein can be used forocclusion-crossing within blood vessels. Advantageously, the devices canadvantageously provide increased trackability through bending/steeringand high imaging speed during such crossing.

Additional details pertinent to the present invention, includingmaterials and manufacturing techniques, may be employed as within thelevel of those with skill in the relevant art. The same may hold truewith respect to method-based aspects of the invention in terms ofadditional acts commonly or logically employed. Also, it is contemplatedthat any optional feature of the inventive variations described may beset forth and claimed independently, or in combination with any one ormore of the features described herein. Likewise, reference to a singularitem, includes the possibility that there are a plurality of the sameitems present. More specifically, as used herein and in the appendedclaims, the singular forms “a,” “and,” “said,” and “the” include pluralreferents unless the context clearly dictates otherwise. It is furthernoted that the claims may be drafted to exclude any optional element. Assuch, this statement is intended to serve as antecedent basis for use ofsuch exclusive terminology as “solely,” “only” and the like inconnection with the recitation of claim elements, or use of a “negative”limitation. Unless defined otherwise herein, all technical andscientific terms used herein have the same meaning as commonlyunderstood by one of ordinary skill in the art to which this inventionbelongs. The breadth of the present invention is not to be limited bythe subject specification, but rather only by the plain meaning of theclaim terms employed.

When a feature or element is herein referred to as being “on” anotherfeature or element, it can be directly on the other feature or elementor intervening features and/or elements may also be present. Incontrast, when a feature or element is referred to as being “directlyon” another feature or element, there are no intervening features orelements present. It will also be understood that, when a feature orelement is referred to as being “connected”, “attached” or “coupled” toanother feature or element, it can be directly connected, attached orcoupled to the other feature or element or intervening features orelements may be present. In contrast, when a feature or element isreferred to as being “directly connected”, “directly attached” or“directly coupled” to another feature or element, there are nointervening features or elements present. Although described or shownwith respect to one embodiment, the features and elements so describedor shown can apply to other embodiments. It will also be appreciated bythose of skill in the art that references to a structure or feature thatis disposed “adjacent” another feature may have portions that overlap orunderlie the adjacent feature.

Terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention.For example, as used herein, the singular forms “a”, “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises” and/or “comprising,” when used in this specification,specify the presence of stated features, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, steps, operations, elements, components, and/orgroups thereof. As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed items and may beabbreviated as “/”.

Spatially relative terms, such as “under”, “below”, “lower”, “over”,“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if a device in thefigures is inverted, elements described as “under” or “beneath” otherelements or features would then be oriented “over” the other elements orfeatures. Thus, the exemplary term “under” can encompass both anorientation of over and under. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly. Similarly, the terms“upwardly”, “downwardly”, “vertical”, “horizontal” and the like are usedherein for the purpose of explanation only unless specifically indicatedotherwise.

Although the terms “first” and “second” may be used herein to describevarious features/elements, these features/elements should not be limitedby these terms, unless the context indicates otherwise. These terms maybe used to distinguish one feature/element from another feature/element.Thus, a first feature/element discussed below could be termed a secondfeature/element, and similarly, a second feature/element discussed belowcould be termed a first feature/element without departing from theteachings of the present invention.

As used herein in the specification and claims, including as used in theexamples and unless otherwise expressly specified, all numbers may beread as if prefaced by the word “about” or “approximately,” even if theterm does not expressly appear. The phrase “about” or “approximately”may be used when describing magnitude and/or position to indicate thatthe value and/or position described is within a reasonable expectedrange of values and/or positions. For example, a numeric value may havea value that is +/−0.1% of the stated value (or range of values), +/−1%of the stated value (or range of values), +/−2% of the stated value (orrange of values), +/−5% of the stated value (or range of values), +/−10%of the stated value (or range of values), etc. Any numerical rangerecited herein is intended to include all sub-ranges subsumed therein.

What is claimed is:
 1. An occlusion crossing device comprising: arotatable drive shaft having an optical fiber used to generate imagesand a distal end with a drill tip; and an outer shaft having a lumen foraccommodating the drive shaft, the outer shaft removably coupled to thedrive shaft such that the drive shaft can rotate within the lumen whencoupled to the outer shaft, an inner portion of the outer shaftconfigured to engage with the drive shaft when a force is applied to thedrive shaft in a longitudinal direction to bend the outer shaft.
 2. Theocclusion crossing device of claim 1, wherein the outer shaft includes abackbone configured to bend the outer shaft in a predetermined directionwhen the force is applied to the drive shaft.
 3. The occlusion crossingdevice of claim 1, wherein a distal region of the outer shaft isconfigured to bend when the force is applied to the drive shaft.
 4. Theocclusion crossing device of claim 1, wherein the optical fiber isconfigured to rotate with the drive shaft.
 5. The occlusion crossingdevice of claim 2, wherein the backbone causes the outer shaft to bendtowards the backbone.
 6. The occlusion crossing device of claim 2,wherein the outer shaft includes circumferential cut on a side of theouter shaft opposite the backbone.
 7. The occlusion crossing device ofclaim 1, wherein the force is a pushing force applied in a distaldirection or a pulling force applied in a proximal direction.
 8. Theocclusion crossing device of claim 1, wherein the drive shaft includesan annular member configured to engage with an inner lip of the outershaft to bend the outer shaft when the drive shaft is pushed distally.9. The occlusion crossing device of claim 1, wherein the drive shaftincludes an annular member configured to engage with an inner lip of theouter shaft to bend the outer shaft when the drive shaft is pulledproximally.
 10. The occlusion crossing device of claim 1, wherein thedrive shaft includes the optical fiber that extends through the driveshaft.
 11. The occlusion crossing device of claim 1, wherein the outershaft further includes a guidewire lumen.
 12. The occlusion crossingdevice of claim 11, wherein the outer shaft includes circumferentialcuts on a side of the outer shaft opposite the guidewire lumen.
 13. Amethod of crossing an occlusion, the method comprising: inserting adevice into a blood vessel having an occlusion therein, the devicehaving a drive shaft within a lumen of an outer shaft; bending the outershaft by applying a force to the drive shaft in a longitudinal directionwhile the drive shaft is coupled with the outer shaft, wherein an innerportion of the outer shaft engages with the drive shaft when the forceis applied to the drive shaft; rotating the drive shaft such that adrill tip at a distal end of the drive shaft drills through theocclusion; generating images of using an optical fiber coupled to thedrive shaft; and removing the drive shaft from the outer shaft while theouter shaft is in the blood vessel.
 14. The method of claim 13, whereinthe outer shaft includes a backbone configured to bend the outer shaftin a predetermined direction when the force is applied to the driveshaft.
 15. The method of claim 14, further comprising inserting aguidewire through the outer shaft.
 16. The method of claim 13, furthercomprising generating the images while the optical fiber rotates withthe drive shaft.
 17. The method of claim 13, wherein the draft shaft isdisplaced longitudinally by a distance of between about 0.125 inches toabout 0.2 inches with respect to the outer shaft when the force isapplied to the drive shaft.
 18. The method of claim 13, wherein theforce is a pushing force applied in a distal direction or a pullingforce applied in a proximal direction.
 19. The method of claim 13,wherein bending the outer shaft includes causing an annular member ofthe drive shaft to engage with an inner lip of the outer shaft.